From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f74.google.com (mail-pj1-f74.google.com [209.85.216.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 93A1B1DDA39 for ; Tue, 28 Jan 2025 06:33:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738046001; cv=none; b=fPRcpYr8UF0sFgb7Ynk1JUqpAfeEZxosXI4C+ZUJiJjxoK4HZP5pIcqmxHSmPLMkWSsAGhBZq3n5vG/O0yfpF7X1XOuz30ChegOfufplEa1m5QxrPz39oTXgoxw65GiaEskgGKWyLMh3oVx9+oQ/IUoLgVGAsBIVJP/zhmuDOy8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738046001; c=relaxed/simple; bh=YSdBmDapVhVN/AMGjsszhz99SkP7ZE79dPF1jBB7FA0=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=G/53q+hoVp6dPT2ob87/sNoH/zlCT73/DaDB8WDT62gwlkg3vutoJGynJdLbS7+KpuiYqjXCM+u2o31bk0XGiJ6ppMVCF2M06Y1dAfl4EfzxZg4KlBwyCvOXZrWdeyuw2BhM9NsJ6Hgq6R1qKaGTtod0VcUOGv9VzOu7Wq+0v3M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--jstultz.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=ufLeGeIJ; arc=none smtp.client-ip=209.85.216.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--jstultz.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ufLeGeIJ" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-2ef9204f898so10242733a91.2 for ; Mon, 27 Jan 2025 22:33:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1738045999; x=1738650799; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=t+Cn+liEdvLPO77KJM0EW/9DM3AYnRCEIQ5r2A6QiYU=; b=ufLeGeIJTj4Pw8DKCXxm/oZOX6tuNaf9x0H9dcFcQ/3xj3I8meF+0QXzUM+YEaUS+p wq+iWIC8KolNnbo0X5y6D2H+s7xwOZT0JY3g8GlBoWf4AM8rFGiEdwmle/7XC8bjXxVS a+63283Y8Ap9D8cJFFQn+C+URuDOHsirZYhS4XI4zc2mrGIQn6WjUH1UQ9iH8KWHegnh gR9pCD/NrrGu+a8MUhYykNSOLFuv6SmmY4hkkYws2W/ak3pSpxxGks1RHIuJkznDBWEN JpQzbEj98X2ygmoyzrbTPPeQFSxr015fBGrwm5tU6njMsgrhC8YHweOFxTepEO7v787W KZ4g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1738045999; x=1738650799; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=t+Cn+liEdvLPO77KJM0EW/9DM3AYnRCEIQ5r2A6QiYU=; b=FN2YgMJ9EicW71xPg3pBLvGoN9lgX6UjvM7EC8knxmghpKk7/l1L3YkNJkcxufxUfe B17CCBQyYLHvHI4phq9XFMIv7JDtKrbPO/vCkeW9tyZC8w7S95hgX8JANauWeO7KS8iF e+AUlWPHWZ+veH9GwiSthV/XkL0fxdeQbMyBuXhFss8n+twJMBRTbmsPTxwvbBTreBA0 pk3XoKSK/YULmP/QFV4Fgxl7uxs/vmyfDNqjJeCYK3vYzLJFjhEckcJpT/59H6c9TOqm lESj7AXHlbQBILZppaREXmKLQFQ1mj2yQQ2BuZ57wpb7TxQTt04019M6JzPAxMFv/NqE 4C/w== X-Gm-Message-State: AOJu0YxiX9XK8xRbSe/mXf6a3IbfPzB8wo6w6S0jOc3+1i/h1m8RP34c QBmUBbKP8vKiZ3qIb+yngSdwJSs3nlHxIPl0TJgExadEJzhJFg4IUGDOMewW4k2JbAeHjAhc/Vz nEXuk44Ns7tj0trCSefrMoO8315kKMKYI42qbm2OJZoQd79gSzg6IxECap1OUdIxOPXtRfbppK1 hZGbXgCq5+8hAHMmBTCpfW3R/ESeqaw8uKK2stY5PDgje2 X-Google-Smtp-Source: AGHT+IHPABKmtyKfkA6jaP5IMQa8z+1SqYcIcf0W1j5HpldIP91Ccu6kXjpwh/Xb0RMeHdfEu+732LHJ2R0D X-Received: from pfbcq14.prod.google.com ([2002:a05:6a00:330e:b0:72d:5313:d4ab]) (user=jstultz job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:1412:b0:71e:4930:162c with SMTP id d2e1a72fcca58-72daf94f6a5mr61193755b3a.6.1738045998681; Mon, 27 Jan 2025 22:33:18 -0800 (PST) Date: Mon, 27 Jan 2025 22:32:55 -0800 In-Reply-To: <20250128063301.3879317-1-jstultz@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250128063301.3879317-1-jstultz@google.com> X-Mailer: git-send-email 2.48.1.262.g85cc9f2d1e-goog Message-ID: <20250128063301.3879317-4-jstultz@google.com> Subject: [RFC][PATCH 3/3] Kconfig: Add CONFIG_DYN_HZ_DEFAULT to specify the default dynhz= boot option value From: John Stultz To: LKML Cc: John Stultz , Anna-Maria Behnsen , Frederic Weisbecker , Ingo Molnar , Thomas Gleixner , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , Stephen Boyd , Yury Norov , Bitao Hu , Andrew Morton , kernel-team@android.com Content-Type: text/plain; charset="UTF-8" Allow a default dynhz= boot option value to be specified via config. Cc: Anna-Maria Behnsen Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: Juri Lelli Cc: Vincent Guittot Cc: Dietmar Eggemann Cc: Steven Rostedt Cc: Ben Segall Cc: Mel Gorman Cc: Valentin Schneider Cc: Stephen Boyd Cc: Yury Norov Cc: Bitao Hu Cc: Andrew Morton Cc: kernel-team@android.com Signed-off-by: John Stultz --- kernel/Kconfig.hz | 10 ++++++++++ kernel/time/tick-common.c | 2 +- 2 files changed, 11 insertions(+), 1 deletion(-) diff --git a/kernel/Kconfig.hz b/kernel/Kconfig.hz index 76714317674c5..27ad1400ad64e 100644 --- a/kernel/Kconfig.hz +++ b/kernel/Kconfig.hz @@ -64,5 +64,15 @@ config DYN_HZ build time configured HZ value. If you are unsure, say no. +config DYN_HZ_DEFAULT + int "Default DynHZ value (valid range: 100-CONFIG_HZ)" + depends on DYN_HZ + default HZ + range 100 HZ + help + Default value for dynhz. This allows ticks to be configured + to arrive at slower than HZ rates. This is useful when you + want to allow boot-time configurable tick rates. + config SCHED_HRTICK def_bool HIGH_RES_TIMERS diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c index 75fd9dadb8273..46463bfb75d3d 100644 --- a/kernel/time/tick-common.c +++ b/kernel/time/tick-common.c @@ -81,7 +81,7 @@ int tick_is_oneshot_available(void) } #ifdef CONFIG_DYN_HZ -long long dyn_tick_nsec = TICK_NSEC; +long long dyn_tick_nsec = TICK_NSEC * HZ / CONFIG_DYN_HZ_DEFAULT; static int __init set_dyn_hz(char *str) { -- 2.48.1.262.g85cc9f2d1e-goog